Although City had a midfielder playing in defence (surprising given how much they spend that they don't have more depth in that area), that should not take anything away from Cardiff. A victory well deserved it seems, showing even the top teams can be got at if you have the right game plan.

If United must buy a defender, it should be another right-back. Jones is OK cover but he's obviously a central defender.
This young guy Varela is a long-term prospect, so some solid cover for Rafael needs to come in.